Sheep&#39;s foot tamper



, upon the end of the shank, which 3,640,638 Patented June 26, 1962 ice 3,040,638 SIEEPS FODT TAMPER Ray N. Atkinson, Burlingame, Caiifl, assignor to Guy F.

Atkinson Company, South San Francisco, Calif., a corporation of Nevada Filed Feb. 18, 1959, Ser. No. 794,043

6 Claims. (CI. 9450) This invention relates sheeps foot type.

Conventional tampers of the above type generally consist of one or more drums rotatably secured to a frame which is tractor drawn or self propelled and which may be adapted to contain water or like ballast. A plurality of tamping feet are mounted upon the peripheral wall of the drum whereby the end of each individual foot applies a compressing or tamping action upon the soil, as the device is moved over a ground surface. For proper tamping action it is generally considered that the length of each tamping foot from the outside surface of the drum, and also that the end area of the tamping foot, should be maintained at nearly their original dimensions. In practice the original proportions are rapidly lost by wear during usage, thus necessitating frequent reconditioning. To facilitate reconditioning, it is common to use a shank attached to the drum, together with a cap socketed can be replaced when the cap wears beyond the required specifications. The tamping ends of such caps present fiat or substantially flat surfaces, whereby the effective tamping action is optimum when the cap is first applied and gradually becomes less effective as the cap wears and the configuration of the cap changes until it has the appearance of being pointed.

In general it is an object of the present invention to provide a tamping foot cap which will provide longer useful life without requiring repair or replacement.

Another object of the invention is to provide a sheeps foot cap which has a novel wear pattern in usage, and which in particular maintains a configuration for good tamping action over a relatively long period of usage.

Additional objects and features of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

FIGURE 1 is a side elevational view illustrating a conventional type of sheeps foot tamper.

FIGURE 2 is an enlarged cross sectional detail illustrating a sheeps foot cap incorporating the present invention, and applied to a shank.

The conventional tamping equipment shown in FIG- URE 1 consists of a drum 10 which is rotatably attached to the frame 11. While the tamper maybe self propelled, in most instances the frame 11 is attached to a tractor.

generally to soil tampers of the The peripheral wall of the drum carries a plurality of spaced tamping feet 12.

As shown particularly in FIGURE 2., each foot consists of a shank 13 which may be a steel casting or forging, and which has its base attached to the wall of the drum as by weld connection 14. A cap 16 is socketed upon the end of the shank, and may likewise be a steel casting or forging. The cap is shown provided with a tapered bore 17, for seating upon the end of the shank. The caps may be attached to the shank by welding or other means, and form effective tamping heads.

In accordance with the present invention, the cap 16 has its tamping end formed by a raised portion or rim 18, which surrounds a central cavity or depression 19. While the head in some instances may be square in section, in this instance it is annular whereby the rim 18 is annular and the recess 19 circular in section. As shown, the radial thickness of the rim 18 is somewhat less than onehalf the radius of the head. By way of example, the radius. of the head may be 1% inches, and the rim inch thick. v

The depression 19 has a substantial depth which preferably is at least equal to the radial thickness of the rim 18. In the proportions illustrated, the depression 19 is substantially greater in'depth than the thickness of the rim. For the example specified above, the' depression may have a depth of about 1% inches, and the wall thickness at the bottom of the recess, about /2 inch.

The cap construction described above possesses certain novel characteristics. When initially applied, and before there has been any substantial amount of wear, the cap presents a flat end face having an area substantially equal to the cross sectional area of the head at its greatest diameter. The depression 19 becomes packed with soil, and therefore serves as a part of the tamping area, the same as if the depression were not present.

As the end of the cap wears away in usage, the wear occurs completely within the area of the rim 18, because the soil packed in the recess 19, prevents any wear upon the bottom surface 21. Dotted lines 22, 23 and 24 represent progressivewear upon the rim. It will be noted that wear must proceed to the configuration indicated by line 24, before further wear causes a serious decrease in the diameter of thehead, in the region of the end of the shank. When wear reaches the dotted line 24, the tamper still presents a relatively unsharpened configuration, particularly when contrasted with the sharpened configuration attained by caps of conventional construction. Therefore, for the period of usage required to wear the cap to the dotted line 24, the cap provides good tamping action. In general the amount of time required to wear the cap to the point indicated by dotted line 24 is relatively long compared to a cap of conventional construction, thus minimizing servicing of the equipment, for a given amount of usage.

I claim:

l. A soil tamper of the sheeps foot type, comprising a drum, a plurality of tamping feet carried by said drum, each of said tamping feet including a shank secured to the drum and a metal cap carried by the shank, said cap comprising a body having a tamping end formed with a raised rim, said raised rim defining an open and clear central depression, means securing said cap to said shank, said rim in' usage being worn away without substantial wear of the metal forming the bottom of the depression.

2. A soil tamper of the sheeps foot type comprising a drum, a plurality of tamping feet carried by said drum, each of said tamping feet including a shank secured to the drum and a metal cap carried by the shank, said cap comprising a body having a tamping end formed with a raised annular rim, said raised rim defining an open and clear central depression which is circular in section, means securing saidcap to said shank, said rim in usage being worn away without substantial wear of the metal forming the bottom of the depression.

' 3. A soil tamper of the sheeps foot type comprising a drum, a plurality of tamping feet carried by said drum, each of said tamping feet including a shank secured to the drum and a metal cap carried by the shank, said cap comprising a body having a tamping end formed with a raised annular rim, said raised rim defining an open and clear central depression, the said rim having a heightat least equal to its thickness, means securing said cap to said shank, said rim in usage being worn away without substantial wear of the metal formingthe bottom of the depression.

4. A soil tamper of the sheeps foot type comprising a drum, a plurality of tamping feet carried by said drum, each of said tamping feet including a shank secured to the drum, a head on its outer end, the body of the head having a tarnping end formed with a raised annular rim, said raised rim defining an open and clear central depression, means securing said cap to said shank, the rim in usage being worn away without substantial wear of the metal forming the bottom of the depression.

5. A soil tamper of the sheeps foot type comprising a drum, a plurality of tamping feet carried by said drum, each of 'said tamping feet including a tapered shank secured to the drum, a metal cap carried by the tapered shank, said cap comprising a body having a tamping end and a socket end, said tamping end being formed with a raised rim, said raised rim defining an open and clear central depression, means securing said cap to said shank,

said rim in usage being worn away without substantial wear of the metal forming the bottom of the depression, and said socket end being formed with a tapered bore seating upon the end of such shank.

6. A soil tamper of the sheeps foot type comprising a drum, a plurality of tamping feet carried by said drum, each of said camping feet including a shank secured to the drum and a metal cap carried by the shank, said cap comprising a body having a camping end and a socket end, said tamping end being formed with a raised annular rim, said raised rim defining an open and clear central depression which is circular in section, means securing said cap to said shank, said rim in usage being worn away without substantial Wear of the metal forming the bottom of the depression, and said socket end being formed with a tapered bore seated on said shank.

References Cited in the file of this patent UNITED STATES PATENTS 242,386 Smith May 31, 1881 1,480,364 Saliger Ian. 8, 1924 2,312,471 LOW Mar. 2, 1943 2,562,860 CObi July 31, 1951 FOREIGN PATENTS 463,156 Italy Apr. 18, 1951 1,160,274 France Feb. 24, 1958 

